I spent the last 20 years learning what makes tomato seedlings grow best. Ideal growth under indoor conditions comes from getting as close as possible to full sunlight conditions. It is impossible to get light that intense with lights 2 feet above the seedlings. Bulbs made specifically for indoor growing are best but are not necessary to produce good seedlings. Plants absorb light between the red and blue spectrum reflecting almost everything else. Tomato seedlings particularly benefit from red spectrum for early growth. Broad spectrum bulbs waste more of their output when used as grow lights. So long as they are used for no more than 8 weeks on seedlings, the difference in performance of ordinary fluorescent bulbs is not appreciably different than when using 6500K bulbs. There is however a measurable difference when using bulbs developed specifically for plants. Warning that there are hundreds of documents on the net incorrectly interpreting which frequencies are used in photosynthesis! Do due diligence to find out what recent research has shown.
What is the actual output of fluorescent lights and how does it compare to full direct sunlight? Direct sunlight runs about 2000 mols. Fluorescent lights measured 2 inches from the bulb do not exceed 400 mols. This is not a major issue. It turns out that tomato and pepper seedlings are incapable of using more than about 400 mols. There is a qualified exception that some very expensive high output bulbs can put out significantly more light. Very few people will pay for such expensive bulbs or the ballasts required to drive them. If in doubt, get a light meter from a camera store or from Amazon and verify this to your satisfaction. Remember that only a portion of the output can actually be used by a plant.
I grow about 30,000 tomato and pepper seedlings each year. My starter stand is 6 tiers high with 6 bulbs on each tier and capacity for 24 trays of seed. I typically plant about 1500 seed in each tray. When the seedlings are between 1 and 3 inches tall, I pot them up into individual cells in trays with 48 cells per tray and move them to the greenhouse.
Here is a a tip for growing tomatoes and peppers under lights. This is for plants in individual pots or cups. Often a few seedlings grow significantly faster than others. If the lights are kept 2 inches above the tallest seedlings, the shorter plants won’t get enough light and will fall even further behind. Put the short plants on a box or book or block of wood to raise them up closer to the lights. This will help them catch up to the taller seedlings.
The objective is to have large healthy seedlings properly hardened off to set out when the weather permits.